1. Field of the Invention
The present invention relates to a terminal frame which is used to manufacture electronic devices with lead terminals and a manufacturing system for such terminal frames.
2. Description of Related Art
There is a type of electronic device, such as a piezoelectric resonator, which has lead terminals. This type of electronic device is mounted on a printed circuit board by inserting the lead terminals into through holes of the printed circuit board by an automatic component mounting machine and soldering the lead terminals to lands of the printed circuit board. In manufacturing electronic devices of this type, a terminal frame having a strip which supports metal terminals protruding in parallel from one side is used. The terminals are attached to electronic devices as lead terminals. FIGS. 8 and 9 show prior art terminal frames. FIG. 8 shows a punched terminal frame, and FIG. 9 shows a taped terminal frame.
The punched terminal frame of FIG. 8 comprises a frame 11 which is a strip with a specified width and a plurality of metal terminals 12 which protrude from a side of the frame 11 at specified intervals. The terminal frame is made by punching the frame 11 and the terminals 12 integrally out of sheet metal. The terminal frame of FIG. 9 comprises a frame 14 which is a strip of cardboard or sheet metal and stick-like, such as cylindrical, metal terminals 15. The metal terminals 15 are arranged in line on a surface of the frame 14 and are fixed on the frame 14 by an adhesive tape 16 or the like.
In producing the terminal frame of FIG. 8, after punching the frame 11 and the terminals 12 out of the sheet metal, the rest of the sheet metal is wasted, which is disadvantageous as to cost. An electronic device which is produced using this terminal frame has thin lead terminals. A failure is likely to occur in inserting the lead terminals into through holes of a printed circuit board and in cutting or bending the end portions of the lead terminals which pierce the printed circuit board to the reverse side. A possible measure to avoid these problems is to roll the terminals 12 into cylinders after the punching. However, this measure requires an additional process and increases the cost.
The taped terminal frame of FIG. 9 requires more processes and more parts. Further, the taped terminal frame is not mechanically strong against tension and torsion and is unstable. The metal terminals 15 must be made longer than necessary by an amount about the width of the adhesive tape 16, which is disadvantageous as to cost. In order to comply with a case wherein the terminal frame is heated in manufacturing electronic devices, the frame 14 and the adhesive tape 16 must resist heat, which also increases the cost manufacture.